public class Device
{
    public static Device Create(Type t, Color c) =>
    (t,c) switch
    {
        (typeof(Iphone), Color.Gold) => new GoldIphone()
        (typeof(Ipad), Color.Silver) => new SilverIpad()
         ......
    }

}

public class Iphone : Device
{}
public class GoldenIphone : Iphone
{}
public class Ipad : Device
{}
public class SilverIpad : Ipad
{}